The immune system plays a role in protecting human body from antigens, which are harmful foreign materials. Examples of the antigens may include bacteria, viruses, toxic materials, cancer cells, and blood or tissues of other people or animals. The immune system produces antibodies to respond to and remove these harmful materials. However, when the immune system does not function properly, the immune system cannot distinguish normal health organs of its own from harmful foreign antigens thereby destroying normal tissues, which is called autoimmune disease. In the case of an autoimmune disease, normal tissues are also included in the reaction target. The cause of autoimmune disease is still not clear but there is a theory assuming that microorganisms such as bacteria or drugs may cause autoimmune diseases in those who are specifically inherited with these genes and are thus vulnerable to autoimmune diseases.
Various chemical and biological immune therapies have been developed for the treatment of autoimmune diseases. The typical method of treatment is to deteriorate the overall immune response of the body using a chemical agent such as steroids or an anti-immune cell antibody, for example, to deteriorate the entire immune response of the body including the normal functions of B cells by administering CD22, CD20, CD19, CD74, or antibodies that bind to HLA-DR.
Korean Patent Application Publication No. 2008-0109705 relates to mesenchymal stem cell-mediated autologous dendritic cells with increased immunosuppression, and it discloses dendritic cells with improved T-cell immunosuppression and uses thereof for the treatment of autoimmune diseases.
U.S. Pat. No. 7,074,403 relates to immunotherapy of autoimmune disorders using antibodies which target B-cells, and it discloses antibodies which bind specifically to B-cell antigens.
U.S. Pat. No. 7,473,592 relates to a cell composition for the treatment of immune diseases using a different object, and it discloses T cell composition coated with anti-CD3 and anti-CD28 antibodies.
The traditional methods for treating autoimmune diseases are largely classified into steroid agents and immunosuppressants. However, these methods deteriorate the overall immune system of the body when they are administered for a long period of time, and they thus weaken the overall immune functions to respond to foreign invasion thereby causing side effects, such as, occurring other diseases. Additionally, steroid agents have the side effects of causing systemic dermatitis.
Through the endeavors to discover suitable drugs and methods by screening therapeutic methods for treating autoimmune diseases, the treatment of autoimmune diseases is mainly based on the use of immunosuppressant drags, such as glucocorticoids, calcineurin inhibitors, and antiproliferatives-antimetabolites. However, since these pharmacological therapies act on a variety of targets, they may reduce the immune functions as a whole, or they may have the disadvantage of having different cytotoxic effects due to a long-term use, and thus suppress the immune system in a nonspecific way, thereby exposing patients to a risk of infections and cancer. Since calcineurin and glucocorticoids exhibit an additional disadvantage due to their nephrotoxicity and diabetogenic effects, their uses in several clinical conditions (for example, renal insufficiency, diabetes, and the like) are limited.
For these reasons, patients with immune diseases including autoimmune diseases have had a great interest in therapeutic types considered as “natural”, which have a weak anti-inflammatory effect but with no major adverse effects and can be used as prevention and auxiliary treatment of diseases, and many researchers have a growing interest in the development of nature-derived therapeutic agents.
In this regard, for the development of stable therapeutic agents with less adverse effects, studies have been recently focused on natural materials. Prior arts as such, Korean Patent No. 668067 discloses that phenylbutenoid derivatives isolated from ginger have excellent anti-inflammatory effect, and Korean Patent No. 396526 discloses that xanthorrhizol isolated from Curcuma xanthorrhiza Roxb. has an anti-inflammatory effect and thus can be used for the treatment of inflammations.
Meanwhile, daurinol, an arylnaphthalene lignan, is a single chemical component, which was first isolated from Haplophyllum dauricum, the medicinal plant of Mongolia, by the present inventors in early 1980s. The daurinol was also isolated from Haplophyllum cappadocicum, the same family but a different plant (Batsuren D, et al., Chemistry of Natural Compounds, 17, 223-225, 1982; Gozler B, et al., Phytochemistry, 31, 2473-2475, 1992). However, its pharmacological effect has never been reported yet. Haplophyllum sp. plants are perennial grasses and widely spread in central Asia. They have been used for the traditional folk remedy for various diseases over hundreds of years.
Under these circumstances, the present inventors have discovered that a daurinol compound has the effect of inhibiting the production of IL-17 and TNF-α, which are inflammation inducing materials, and thus it can be used as a therapeutic agent for treating immune diseases, thereby completing the present invention.